Systems known as thin client systems are known. In the thin client system, only minimum functionality is given to a client, and the system is configured to manage resources such as applications and files on a server.
In practice, even while the thin client system makes the client display processing results from processing actually executed by the server and data actually saved on the server, configuration is made such that it appears that the client is the main executer of processing and holder of data.
Conversion gateways exist that convert old remote screen control protocols to new remote screen control protocols with superior functionality. Thin client systems also exist that have conversion gateways located between the client and server. In these cases, the conversion gateway receives the screen data from the server by the old remote screen control protocol, converts the screen data to the new remote screen control protocol, and transfers this data to the client.
As illustrated in FIG. 24, conversion gateway 506 may be in communication with plural clients 502A1, 502A2 and so on. In such cases, the conversion gateway 506 performs intermediate processing of processing (sessions) requested from each client 502A1, etc. The conversion gateway 506 performs the conversion processing to the new remote screen control protocol for each session. Specifically, “screen acquisition”, “screen drawing”, “compression” and “transfer” are performed. In more detail, during “screen acquisition”, data including screen data is acquired from the server. During “screen drawing”, the acquired screen data is decompressed and drawn to the frame buffer as bitmap data. During “compression”, isolation and compression is performed on regions of data in frame buffer that need be transmitted. During “transfer”, transfer of the compressed data is performed.